A machine (e.g., server machine or a user's device, which may be denoted a “first device”) may form all or part of a network-based system (e.g., a system of modules with access to a network) that provides one or more services to one or more users of the network-based system. Examples of network-based systems include business management systems, project management systems, workflow management systems, event coordination systems (e.g., calendaring systems or scheduling systems), commerce systems (e.g., shopping websites or auction websites), publication systems (e.g., classified advertisement websites), social network systems (e.g., Facebook® or Twitter®), and any suitable combinations thereof.
In some situations, users of a network-based system may access a service from various devices (e.g., smart phones, set-top boxes, personal computers, or tablet computers). For example, one user may access a service from his smart phone by connecting to the network-based system via a network (e.g., the Internet), while another user may access the service from her tablet computer by connecting to the network-based system via another network (e.g., a private network).